Chapter 7Skeletal System: Appendicular Skeleton
• Pectoral girdle• Pelvic girdle • Upper limbs• Lower limbs
Pectoral (Shoulder) Girdle
• Consists of scapula and clavicle • Clavicle articulates with sternum • Clavicle articulates with scapula • Scapula held in place by muscle only• Upper limb attached to pectoral girdle at
shoulder
Clavicle (collarbone)
• S-shaped bone with two curves– medial curve convex anteriorly/lateral one concave anteriorly
• Extends from sternum to scapula above 1st rib• Fracture site is junction of curves • Ligaments attached to clavicle stabilize its position.
Scapula
• Triangular flat bone found in upper back region
posterior
Upper Extremity
• Each upper limb = 30 bones– humerus within the arm– ulna & radius within the forearm– carpal bones within the wrist– metacarpal bones within the palm– phalanges in the fingers
Pelvic Girdle and Hip Bones
• Pelvic girdle = two hipbones united at pubic symphysis– articulate posteriorly with sacrum at sacroiliac joints
• Each hip bone = ilium, pubis, and ischium– fuse after birth at acetabulum
• Bony pelvis = 2 hip bones, sacrum and coccyx
Ilium, Ischium and Pubis
Pelvis
• Pelvis = sacrum, coccyx & 2 hip bones
• Pelvic brim– sacral promontory to
symphysis pubis– separates false from true
pelvis– false pelvis holds only
abdominal organs• Inlet & outlet• Pelvic axis = path of
babies head
Female and Male Skeletons• Male skeleton
– larger and heavier– larger articular surfaces– larger muscle
attachments• Female pelvis
– wider & shallower– larger pelvic inlet &
outlet– more space in true
pelvis– pubic arch >90 degrees
Female Male
Lower Extremity
• Each lower limb = 30 bones– femur and patella within the thigh– tibia & fibula within the leg– tarsal bones in the foot– metatarsals within the forefoot– phalanges in the toes
Arches of the Foot• Function
– distribute body weight over foot– yield & spring back when weight is lifted
• Longitudinal arches along each side of foot• Transverse arch across midfoot region
– navicular, cuneiforms & bases of metatarsals
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